This page, Water Quality Assessments, is part of
This page, Water Quality Assessments, is offered by

Water Quality Assessments

Look here for reports on the condition of watersheds in Massachusetts.

MassDEP's Watershed Planning Program (WPP) conducts monitoring and assessment activities and reports its findings to the United States Environmental Protection Agency (USEPA) and the public as required by the federal Clean Water Act (CWA). Water quality assessments are conducted to evaluate the ecological and recreational ("fishable/swimmable") condition of Massachusetts’ surface waters.

Reporting Requirements

Sections 305(b), 314, and 303(d) of the CWA direct states to monitor and report on the quality of their surface waters and whether they support designated uses. The WPP fulfills these monitoring and reporting requirements and evaluates the support of uses designated in the state’s Surface Water Quality Standards (SWQS) Regulations (314 CMR 4.00). The designated uses include aquatic life (such as fish, other aquatic life, and wildlife); fish consumption; public water supply; shellfish harvesting; primary (e.g., swimming) and secondary (e.g., boating) contact-recreation; and aesthetics.

Data Used in Assessments

Validated water quality monitoring data are provided by the WPP monitoring program (WPP Monitoring Data).
Additionally, quality-assured data are provided from watershed associations and other outside groups (External Data Submittals).

The above data sources, along with other state and federal agency data, are used by the WPP to assess and report on the state’s surface water quality conditions.

Assessment and Listing Methodology

The Massachusetts Consolidated Assessment and Listing Methodology (CALM) Guidance Manual (see Additional Resources below) describes how data are used to assess surface water quality conditions, and the process used to identify causes and sources of impairment. It also describes the categorization of the assessed waters as to whether they meet designated uses. Waters that are impaired for one or more uses due to pollutant(s) are listed on the 303(d) “List of Impaired Waters” (“303(d) List”).

The CWA requires states to submit reports on the designated-use-support status of their water bodies every 2 years. These "Integrated List of Waters" reports (IR) combine the CWA reporting requirements of sections 305(b) (“Summary of Water Quality”) and the 303(d) List. Category 5 of the IR is assigned to the surface waters on the 303(d) List that require restoration using cleanup plans, or Total Maximum Daily Loads (TMDL). The 303(d) List is subject to public review and comment and must be approved by the US Environmental Protection Agency.

Additional Resources

Integrated Lists of Waters
Total Maximum Daily Loads (TMDLs)
WPP Water Quality Technical Memoranda
2018 Consolidated Assessment and Listing Methodology Guidance (PDF 3.59 MB)
2016 Consolidated Assessment and Listing Methodology Guidance (PDF 4.36 MB)
2012 Assessment Methodology Guidance Manual (PDF 1.43 MB)

Water Quality Assessment Reports by Watershed (WPP survey years 1997 through 2004)

Water Quality Assessment Reports, Blackstone through Islands Watersheds

Water Quality Assessment Reports, Merrimack through Weymouth & Weir Watersheds

Water Quality at DCR State Beaches

  • Final Beach Water Quality Report
    The complete report issued to the Senate and the House of Representatives on the water quality at beaches under the care and control of the Department of Conservation and Recreation, 2008-2012. This special report was submitted in fulfillment of House Bill No. 4384.
  • Final Beach Water Quality Report
    Main body of the report on the water quality at beaches under the care and control of the Department of Conservation and Recreation, 2008-2012.
  • Appendices to Beach Report
    Appendices to the Beaches Water Quality Report, 2008-2012.
Feedback